__set_task_cpu(p, new_cpu);
}
+static void __migrate_swap_task(struct task_struct *p, int cpu)
+{
+ if (p->on_rq) {
+ struct rq *src_rq, *dst_rq;
+
+ src_rq = task_rq(p);
+ dst_rq = cpu_rq(cpu);
+
+ deactivate_task(src_rq, p, 0);
+ set_task_cpu(p, cpu);
+ activate_task(dst_rq, p, 0);
+ check_preempt_curr(dst_rq, p, 0);
+ } else {
+ /*
+ * Task isn't running anymore; make it appear like we migrated
+ * it before it went to sleep. This means on wakeup we make the
+ * previous cpu our targer instead of where it really is.
+ */
+ p->wake_cpu = cpu;
+ }
+}
+
+struct migration_swap_arg {
+ struct task_struct *src_task, *dst_task;
+ int src_cpu, dst_cpu;
+};
+
+static int migrate_swap_stop(void *data)
+{
+ struct migration_swap_arg *arg = data;
+ struct rq *src_rq, *dst_rq;
+ int ret = -EAGAIN;
+
+ src_rq = cpu_rq(arg->src_cpu);
+ dst_rq = cpu_rq(arg->dst_cpu);
+
+ double_raw_lock(&arg->src_task->pi_lock,
+ &arg->dst_task->pi_lock);
+ double_rq_lock(src_rq, dst_rq);
+ if (task_cpu(arg->dst_task) != arg->dst_cpu)
+ goto unlock;
+
+ if (task_cpu(arg->src_task) != arg->src_cpu)
+ goto unlock;
+
+ if (!cpumask_test_cpu(arg->dst_cpu, tsk_cpus_allowed(arg->src_task)))
+ goto unlock;
+
+ if (!cpumask_test_cpu(arg->src_cpu, tsk_cpus_allowed(arg->dst_task)))
+ goto unlock;
+
+ __migrate_swap_task(arg->src_task, arg->dst_cpu);
+ __migrate_swap_task(arg->dst_task, arg->src_cpu);
+
+ ret = 0;
+
+unlock:
+ double_rq_unlock(src_rq, dst_rq);
+ raw_spin_unlock(&arg->dst_task->pi_lock);
+ raw_spin_unlock(&arg->src_task->pi_lock);
+
+ return ret;
+}
+
+/*
+ * Cross migrate two tasks
+ */
+int migrate_swap(struct task_struct *cur, struct task_struct *p)
+{
+ struct migration_swap_arg arg;
+ int ret = -EINVAL;
+
+ arg = (struct migration_swap_arg){
+ .src_task = cur,
+ .src_cpu = task_cpu(cur),
+ .dst_task = p,
+ .dst_cpu = task_cpu(p),
+ };
+
+ if (arg.src_cpu == arg.dst_cpu)
+ goto out;
+
+ /*
+ * These three tests are all lockless; this is OK since all of them
+ * will be re-checked with proper locks held further down the line.
+ */
+ if (!cpu_active(arg.src_cpu) || !cpu_active(arg.dst_cpu))
+ goto out;
+
+ if (!cpumask_test_cpu(arg.dst_cpu, tsk_cpus_allowed(arg.src_task)))
+ goto out;
+
+ if (!cpumask_test_cpu(arg.src_cpu, tsk_cpus_allowed(arg.dst_task)))
+ goto out;
+
+ ret = stop_two_cpus(arg.dst_cpu, arg.src_cpu, migrate_swap_stop, &arg);
+
+out:
+ return ret;
+}
+
struct migration_arg {
struct task_struct *task;
int dest_cpu;
* The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable.
*/
static inline
-int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
+int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags)
{
- int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags);
+ cpu = p->sched_class->select_task_rq(p, cpu, sd_flags, wake_flags);
/*
* In order not to call set_task_cpu() on a blocking task we need
if (p->sched_class->task_waking)
p->sched_class->task_waking(p);
- cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
+ cpu = select_task_rq(p, p->wake_cpu, SD_BALANCE_WAKE, wake_flags);
if (task_cpu(p) != cpu) {
wake_flags |= WF_MIGRATED;
set_task_cpu(p, cpu);
*
* __sched_fork() is basic setup used by init_idle() too:
*/
-static void __sched_fork(struct task_struct *p)
+static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
{
p->on_rq = 0;
#ifdef CONFIG_NUMA_BALANCING
if (p->mm && atomic_read(&p->mm->mm_users) == 1) {
p->mm->numa_next_scan = jiffies + msecs_to_jiffies(sysctl_numa_balancing_scan_delay);
- p->mm->numa_next_reset = jiffies + msecs_to_jiffies(sysctl_numa_balancing_scan_period_reset);
p->mm->numa_scan_seq = 0;
}
+ if (clone_flags & CLONE_VM)
+ p->numa_preferred_nid = current->numa_preferred_nid;
+ else
+ p->numa_preferred_nid = -1;
+
p->node_stamp = 0ULL;
p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0;
- p->numa_migrate_seq = p->mm ? p->mm->numa_scan_seq - 1 : 0;
p->numa_scan_period = sysctl_numa_balancing_scan_delay;
p->numa_work.next = &p->numa_work;
p->numa_faults = NULL;
+ p->numa_faults_buffer = NULL;
+
+ INIT_LIST_HEAD(&p->numa_entry);
+ p->numa_group = NULL;
#endif /* CONFIG_NUMA_BALANCING */
}
/*
* fork()/clone()-time setup:
*/
-void sched_fork(struct task_struct *p)
+void sched_fork(unsigned long clone_flags, struct task_struct *p)
{
unsigned long flags;
int cpu = get_cpu();
- __sched_fork(p);
+ __sched_fork(clone_flags, p);
/*
* We mark the process as running here. This guarantees that
* nobody will actually run it, and a signal or other external
* - cpus_allowed can change in the fork path
* - any previously selected cpu might disappear through hotplug
*/
- set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0));
+ set_task_cpu(p, select_task_rq(p, task_cpu(p), SD_BALANCE_FORK, 0));
#endif
/* Initialize new task's runnable average */
int dest_cpu;
raw_spin_lock_irqsave(&p->pi_lock, flags);
- dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0);
+ dest_cpu = p->sched_class->select_task_rq(p, task_cpu(p), SD_BALANCE_EXEC, 0);
if (dest_cpu == smp_processor_id())
goto unlock;
struct task_struct *p;
int retval;
- get_online_cpus();
rcu_read_lock();
p = find_process_by_pid(pid);
free_cpumask_var(cpus_allowed);
out_put_task:
put_task_struct(p);
- put_online_cpus();
return retval;
}
unsigned long flags;
int retval;
- get_online_cpus();
rcu_read_lock();
retval = -ESRCH;
goto out_unlock;
raw_spin_lock_irqsave(&p->pi_lock, flags);
- cpumask_and(mask, &p->cpus_allowed, cpu_online_mask);
+ cpumask_and(mask, &p->cpus_allowed, cpu_active_mask);
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
out_unlock:
rcu_read_unlock();
- put_online_cpus();
return retval;
}
raw_spin_lock_irqsave(&rq->lock, flags);
- __sched_fork(idle);
+ __sched_fork(0, idle);
idle->state = TASK_RUNNING;
idle->se.exec_start = sched_clock();
return ret;
}
+#ifdef CONFIG_NUMA_BALANCING
+/* Migrate current task p to target_cpu */
+int migrate_task_to(struct task_struct *p, int target_cpu)
+{
+ struct migration_arg arg = { p, target_cpu };
+ int curr_cpu = task_cpu(p);
+
+ if (curr_cpu == target_cpu)
+ return 0;
+
+ if (!cpumask_test_cpu(target_cpu, tsk_cpus_allowed(p)))
+ return -EINVAL;
+
+ /* TODO: This is not properly updating schedstats */
+
+ return stop_one_cpu(curr_cpu, migration_cpu_stop, &arg);
+}
+
+/*
+ * Requeue a task on a given node and accurately track the number of NUMA
+ * tasks on the runqueues
+ */
+void sched_setnuma(struct task_struct *p, int nid)
+{
+ struct rq *rq;
+ unsigned long flags;
+ bool on_rq, running;
+
+ rq = task_rq_lock(p, &flags);
+ on_rq = p->on_rq;
+ running = task_current(rq, p);
+
+ if (on_rq)
+ dequeue_task(rq, p, 0);
+ if (running)
+ p->sched_class->put_prev_task(rq, p);
+
+ p->numa_preferred_nid = nid;
+
+ if (running)
+ p->sched_class->set_curr_task(rq);
+ if (on_rq)
+ enqueue_task(rq, p, 0);
+ task_rq_unlock(rq, p, &flags);
+}
+#endif
+
/*
* migration_cpu_stop - this will be executed by a highprio stopper thread
* and performs thread migration by bumping thread off CPU then
DEFINE_PER_CPU(struct sched_domain *, sd_llc);
DEFINE_PER_CPU(int, sd_llc_size);
DEFINE_PER_CPU(int, sd_llc_id);
+DEFINE_PER_CPU(struct sched_domain *, sd_numa);
static void update_top_cache_domain(int cpu)
{
rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);
per_cpu(sd_llc_size, cpu) = size;
per_cpu(sd_llc_id, cpu) = id;
+
+ sd = lowest_flag_domain(cpu, SD_NUMA);
+ rcu_assign_pointer(per_cpu(sd_numa, cpu), sd);
}
/*
| 0*SD_SHARE_PKG_RESOURCES
| 1*SD_SERIALIZE
| 0*SD_PREFER_SIBLING
+ | 1*SD_NUMA
| sd_local_flags(level)
,
.last_balance = jiffies,
sched_init_numa();
- get_online_cpus();
+ /*
+ * There's no userspace yet to cause hotplug operations; hence all the
+ * cpu masks are stable and all blatant races in the below code cannot
+ * happen.
+ */
mutex_lock(&sched_domains_mutex);
init_sched_domains(cpu_active_mask);
cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
if (cpumask_empty(non_isolated_cpus))
cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
mutex_unlock(&sched_domains_mutex);
- put_online_cpus();
hotcpu_notifier(sched_domains_numa_masks_update, CPU_PRI_SCHED_ACTIVE);
hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE);
projects / linux-2.6-microblaze.git / blobdiff